Enhancing pollutant removal and electricity generation in Sediment Microbial Fuel Cell with nano zero-valent iron

Abstract

A nano zero-valent iron (NZVI) was added into sediments to enhance the capacities of sediment microbial fuel cells (SMFCs) for pollutant removal and electricity generation. Open and closed circuits were applied to confirm the impact of NZVI on the pollutant removal performance of SMFCs. The operation of SMFCs in a closed circuit with 0.06% NZVI produced a current density of 340.8 mA/m 2 . Adding 0.6% NZVI to closed-circuit SMFCs reduced hydrogen sulfide from 12.5 mg/L to 0 mg/L. Moreover, adding NZVI to closed-circuit SMFCs reduced phosphate concentration from 49 mg/L to 11 mg/L. With the same amount of NZVI, the pollutant removal in a closed circuit was higher than that in an open circuit because of the electricity flow at SMFCs. In conclusion, addition of NZVI to SMFCs effectively enhanced the produced current density and reduced the concentrations of hydrogen sulfide and phosphate in sediments. • Addition of NZVI to the anode chamber enhanced electricity production in SMFCs. • The higher current density of 340.8 mA/m2 in SMFC with addition 0.06% of NZVI . • Addition of 0.6% of NZVI reduced phosphate and hydrogen sulfide in sediments. • Excessive NZVI reduces electricity production in SMFCs.